JP2021195876A - Combustion control method for gas turbine - Google Patents

Abstract

To provide a combustion control method for a gas turbine, which materializes stable combustion during a partial load operation to thereby prevent increase of NOx concentration of exhaust gas.SOLUTION: An equivalence ratio of a main fuel at the time of a turbine operation, in which a metal temperature of a turbine blade is equal to or lower than a design value maximum, combustion vibration is equal to or less than a reference value, combustion efficiency is equal to or higher than a reference value, and NOx concentration of exhaust gas is equal to or lower than a regulation value, is obtained by an experiment or an analysis. Also, a relationship between the equivalence ratio and one or both of a turbine inlet gas temperature and a turbine exhaust gas temperature is registered. The turbine inlet gas temperature is measured by an inlet temperature measuring device 104a, or the turbine exhaust gas temperature is measured by an exhaust temperature measuring device 106a. From a relationship between one or both of these measured values and the registered equivalence ratio, an opening of an inlet guide blade 101 is changed and adjusted to attain the equivalent ratio.SELECTED DRAWING: Figure 1

Description

The present invention relates to a combustion control method for a gas turbine, and more particularly to a combustion control method other than at a rated load.

In diffusion combustion, in which combustion gas is injected into the air atmosphere, the combustion gas and air are not sufficiently mixed and combustion is performed in a high concentration state, so that the combustion temperature rises and NOx (nitrogen oxide) is discharged. The concentration becomes high. Therefore, the NOx concentration can be reduced by injecting steam or water into the combustion region to lower the combustion temperature.
However, a large amount of water is required for the amount of fuel supplied, which may reduce the efficiency of the gas turbine plant.

Therefore, diluted premix combustion that enables low NOx to be discharged without injecting water vapor or water is adopted. In the diluted premixed combustion, the combustion gas is mixed with air, and the mixed gas diluted to a low concentration is supplied to the combustion region to perform combustion. Since the combustion temperature of this premixture becomes low, the generation of NOx is suppressed and NOx having a low concentration is discharged.

On the other hand, in order to ensure stable combustion at the rated load, the fuel is operated so as to have an optimum fuel equivalent ratio, which is an index of the fuel concentration in the air-fuel mixture. When the load is high in the rated operation, stable combustion is promoted and NOx emissions are reduced.
While combustion is stable at the rated load, the air supplied becomes excessive at the rated load as compared with the rated load, resulting in lean burn (lean combustion) and incomplete combustion.

By the way, for example, in a facility such as a factory where a gas turbine is installed, a rated load operation is performed in the daytime with full operation, but a partial load operation is often performed at night or on holidays. In addition, when rolling blackouts occur in the event of a disaster such as a typhoon or earthquake, the power generated by the gas turbine is used to transmit power to important facilities such as the server center. Partial load operation with a low load is required. Even during such partial load operation, stable combustion and low NOx emission are required.

At partial load, the amount of fuel required is small and the fuel equivalent ratio is low. If premixed combustion is performed under such conditions, the combustion becomes unstable, and there is a concern that combustion vibration and misfire may occur, and normal operation may not be expected. Stable operation can be expected by performing diffusion combustion, but the amount of NOx emissions will increase as described above.

In order not to cause lean burn at the time of partial load, Patent Document 1 adjusts the amount of air by a variable blade for adjusting the air flow rate provided in front of the compressed air intake, realizes an appropriate fuel-air ratio range, and is harmful. An environmentally friendly gas turbine that reduces emissions has been proposed.

Further, Patent Document 2 describes a gas turbine engine with at least one compressor having at least one row of adjustable variable blades for controlling inlet air mass flow, at least one combustor, and at least one combustor. One turbine is provided and has a control system in which the control system is functionally directly and functionally related to at least one measured temperature value measured upstream of the compressor or the compressor. Gas turbine systems have been proposed that control the position of variable blades with respect to measurable quantities.

Japanese Unexamined Patent Publication No. 61-58928 Japanese Unexamined Patent Publication No. 2011-27106

In the environment-friendly gas turbine described in Patent Document 1, the throttle valve provided in the inlet duct is throttled when the air is excessive at a low load to reduce the air flow rate entering the compressor, and proper combustion is performed in the combustor. It is supposed to be set to the air ratio. Further, the control method of the gas turbine system described in Patent Document 2 controls the position of the variable blade based on the temperature value measured upstream of the compressor and the like.

An object of the present invention is to reduce NOx emissions by enabling stable premixed combustion even under partial load by controlling combustion with an inlet guide blade (IGV: Inlet Guide Vane). ..

In order to achieve the above object, the gas turbine combustion control method according to the present invention includes a compressor, a combustor by premixed combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied. , The inlet guide blades are arranged on the intake side of the compressor to measure either or both of the turbine inlet gas temperature and the turbine exhaust gas temperature, and the fuel equivalent ratio and the turbine inlet gas temperature or turbine set in advance. It is characterized in that the opening area of the inlet guide blade is adjusted with respect to the measured temperature of the turbine inlet gas temperature or the turbine exhaust gas temperature based on the relationship with either one or both of the exhaust gas temperatures.

The equivalent ratio of fuel and air, which stabilizes combustion and produces good NOx emissions, is determined in advance, and the relationship with one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature is determined. Then, using one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature as parameters, the actuator or the like is driven to change the opening degree of the inlet guide blade to adjust the air amount and perform combustion with a stable equivalent ratio. Adjust so that the value can be adjusted.

Further, the combustion control method of the gas turbine according to the present invention includes a compressor, a combustor by premixed combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied, and is provided on the intake side of the compressor. An inlet guide wing is arranged in the turbine, a pilot fuel nozzle is arranged in the center of the inner cylinder of the combustor, and a plurality of premixing pipes equipped with a main fuel nozzle are arranged around the pilot fuel nozzle. Measure either the inlet gas temperature or the turbine exhaust gas temperature, or based on the relationship between the pre-measured and preset fuel equivalent ratio and the turbine inlet gas temperature or the turbine exhaust gas temperature, or both. It is characterized in that the opening area of the inlet guide blade is adjusted with respect to the measured temperature of the turbine inlet gas temperature or the turbine exhaust gas temperature.

That is, the turbine is equipped with a combustor by premixed combustion. A plurality of premixing pipes are installed around a pilot fuel nozzle, and each premixing pipe has a structure in which a main fuel nozzle is arranged.

Further, the combustion control method of the gas turbine according to the present invention includes a compressor, a combustor by premixed combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied, and is provided on the intake side of the compressor. An inlet guide wing is arranged in the turbine, a pilot fuel nozzle is arranged in the center of the inner cylinder of the combustor, and a plurality of premixing pipes equipped with a main fuel nozzle are arranged around the pilot fuel nozzle. Measure either the inlet gas temperature or the turbine exhaust gas temperature, or based on the relationship between the pre-measured and set fuel equivalent ratio and the turbine inlet gas temperature or the turbine exhaust gas temperature, or both. It is characterized by adjusting the number of premixing pipes for injecting the main fuel with respect to the measured temperature of the turbine inlet gas temperature or the turbine exhaust gas temperature.

The amount of main fuel injected from the main fuel nozzle is adjusted by increasing or decreasing the number of premixing pipes with respect to the measured temperature of one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature. For example, when six premixing pipes are provided, the main fuel is injected from all the premixing pipes during the rated load operation, and the injection is performed from the two premixing pipes during the partial load operation. Then, as the load increases, the number of premixed tubes to be injected is increased. The presence or absence of injection is determined by opening and closing the adjusting valve arranged in the supply pipe that supplies the main fuel to the nozzle for the main fuel.

Further, the combustion control method of the gas turbine according to the present invention includes a compressor, a combustor by premixed combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied, and is provided on the intake side of the compressor. An inlet guide wing is arranged in the turbine, a pilot fuel nozzle is arranged in the center of the inner cylinder of the combustor, and a plurality of premixing pipes equipped with a main fuel nozzle are arranged around the pilot fuel nozzle. Measure either the inlet gas temperature or the turbine exhaust gas temperature, or based on the relationship between the pre-measured and set fuel equivalent ratio and the turbine inlet gas temperature or the turbine exhaust gas temperature, or both. It is characterized in that the opening area of the inlet guide blade is adjusted with respect to the measured temperature of the turbine inlet gas temperature or the turbine exhaust gas temperature, and / and the number of premixing pipes for injecting the main fuel is adjusted.

By measuring one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature, one or both of the adjustment of the opening area of the inlet guide blade and the adjustment of the number of injections of the premixing pipe are performed according to the load at that time. It enables stable combustion.

Further, in the above-mentioned combustion control method for a gas turbine, the equivalent ratio is a value that satisfies the respective reference values of the metal temperature of the turbine blade, the combustion vibration, the combustion efficiency, and the NOx concentration of the exhaust gas. It is preferable to obtain a relationship with the inlet gas temperature or the turbine exhaust gas temperature and adjust the opening area of the inlet guide blade from the measured temperature based on this relationship.

When finding the optimum equivalent ratio value,
(1) The metal temperature of the turbine blade is below the design upper limit.
(2) Combustion vibration is below the standard.
(3) Combustion efficiency is above the standard.
(4) The NOx concentration of the exhaust gas is below the regulation value.
The turbine is operated so as to satisfy the above conditions, and the equivalent ratio satisfying the conditions (1) to (4) is found in advance by a test or analysis.

According to the combustion control method of the gas turbine according to the present invention, stable combustion can be performed even during partial load operation, and NOx emissions can be reduced.

It is a graph explaining the control mode in the combustion control method of the gas turbine which concerns on this invention. It is a schematic cross-sectional view which shows the structure of an example of the gas turbine which carries out the combustion control which concerns on this invention. It is a figure explaining the 1st Embodiment of the premixing tube suitable for carrying out the combustion control method which concerns on this invention, and is the perspective view which shows the outline of the premixing tube. It is a front view of the premixing tube shown in FIG. It is sectional drawing which shows cut along the 5-5 line in FIG. It is a top view of the premixing tube shown in FIG. 3 is a cross-sectional view showing the premixer shown in FIG. 3 cut along a plane orthogonal to the axis. FIG. 3A is a cross-sectional view taken along the line 7A-7A in FIG. 4, and FIG. ) Is a 7C-7C line sectional view, and (D) is a 7D-7D line sectional view. It is a development view of the body of the premixing pipe of the gas turbine shown in FIG. It is a figure explaining the 2nd Embodiment of the premixing tube suitable for carrying out the combustion control method which concerns on this invention, and is the perspective view which shows the outline of the premixing tube. It is a front view of the premixing tube shown in FIG. It is sectional drawing which shows along the line 11-11 in FIG. It is a figure explaining the intake state of the air in a premixing tube, and is the cross-sectional view which shows by cutting in the plane along the axis. It is a figure which shows the premixing tube of the structure which takes in air in an axial direction, and is the sectional view corresponding to FIG.

The combustion control method of the gas turbine according to the present invention will be described with reference to the illustrated embodiment.
First, an outline of an embodiment of a gas turbine to be implemented by the combustion control method according to the present invention will be described with reference to FIG.

In the gas turbine 100, the air sucked from the air suction port 101 is supplied to the compressor 102 through the inlet guide blade 101a and compressed, and the compressed air is guided to the combustor 103. The combustor 103 has a double structure of a combustor outer cylinder 103a and a combustor inner cylinder 103b, and compressed air is guided to the outside of the combustor inner cylinder 103b.

On the upper part of the combustor inner cylinder 103b of the combustor 103, an appropriate number of premixing pipes 1 are arranged and mounted at substantially equal intervals on the circumference centered on the axis of the combustor inner cylinder 103b. The lower part of the premixing pipe 1 is communicated with the inside of the combustor inner cylinder 103b, the main fuel nozzle 110 to which the main fuel is supplied is arranged in the upper part, and the main fuel is inside the combustor inner cylinder 103b. Be jetted. The main fuel is separately supplied to each main fuel nozzle 110 from the fuel supply pipe 110a, and the fuel supply pipe 110a is provided with a regulating valve 110b for adjusting the supply amount of the main fuel. By opening and closing the regulating valve 110b, it is possible to adjust, supply and shut off the supply amount of the main fuel. Therefore, the injection amount of the main fuel can be adjusted separately for each of the main fuel nozzles 110. Further, although only one main fuel nozzle 110 is shown in FIG. 2, in any of the plurality of main fuel nozzles 110, the main fuel is similarly supplied by the fuel supply pipe 110a via the regulating valve 110b. Will be supplied.

A pilot fuel nozzle 111 is arranged in the upper center of the combustor inner cylinder 103b, and the pilot fuel is injected into the combustor inner cylinder 103b. The injected pilot fuel is ignited by an ignition device (not shown).
The compressed air guided to the outside of the combustor inner cylinder 103b is guided to the premixing pipe 1 and mixed with the combustion gas of the main fuel to generate a mixed gas, and this mixed gas is burned from the lower part of the premixing pipe 1. It is injected into the inner cylinder 103b to promote combustion, and high-temperature, high-pressure working gas is generated.
The working gas generated by the combustor 103 is guided to the turbine 104 to rotate the turbine blades and rotate the spindle 105. By rotating the spindle 105, the compressor 102 is rotated and a desired output rotation is obtained. The working gas used for the rotation of the turbine 104 becomes exhaust gas and is discharged from the exhaust duct 106.

An inlet temperature measuring device 104a for measuring the turbine inlet gas temperature is provided at the inlet of the turbine 104. Further, the exhaust duct 106 is provided with an exhaust temperature measuring device 106a for measuring the turbine exhaust gas temperature. The turbine inlet gas temperature and the turbine exhaust gas temperature measured by each of the inlet temperature measuring device 104a and the exhaust temperature measuring device 106a are provided to the control device 115.

By the way, when the gas turbine 100 is in operation, the metal temperature of the turbine blade, the combustion vibration, the combustion efficiency, and the NOx concentration of the exhaust gas are measured, and the metal temperature is below the design upper limit value and the combustion vibration is below the standard. Yes, when the combustion efficiency is above the standard and the NOx concentration of the exhaust gas is below the regulation value, the equivalent ratio of fuel and air is obtained, and the equivalent ratio is measured by the inlet temperature measuring device 104a. The relationship between the turbine inlet gas temperature and the turbine exhaust gas temperature measured by the exhaust temperature measuring device 106a is obtained in advance, and the relationship is registered in the control device 115.
For example, the optimum fuel equivalent ratio is found by testing or analysis from the relationship between the turbine blade metal temperature, combustion vibration, combustion efficiency, and NOx concentration of exhaust gas.
In FIG. 1, the vertical axis shows the reference value, the horizontal axis shows the opening degree of the inlet guide blade 101a, the solid line shows the turbine blade metal temperature, the broken line shows the combustion efficiency, the one-dot chain line shows the combustion vibration, and the two-dot chain line shows NOx. The concentrations are shown respectively. Further, C, T, and V on the vertical axis indicate the combustion efficiency of the equivalent ratio in a stable combustion state, the turbine blade metal temperature, and the reference values of the combustion vibration, respectively. The opening adjustment range of the inlet guide blade 101a in which the turbine blade metal temperature is below the reference value (design upper limit) T, the combustion efficiency is above the reference value C, the combustion vibration is below the reference value V, and the NOx concentration is below the regulation value. Find R. The IGV opening degree corresponding to the reference value V is v, the IGV opening degree corresponding to the reference time T is t, and the IGV opening degree corresponding to the reference value C is c. As shown in FIG. 1, the opening degree adjustment range R is an opening degree between the opening degree c and the opening degree t. Then, the relationship between the turbine inlet gas temperature and the turbine exhaust gas temperature when the equivalent ratio for maintaining the stable combustion is obtained is obtained, and this relationship is registered in the control device 115.
The regulation value of the NOx concentration is a value on the side narrowed down from the opening degree t in FIG. 1, and the NOx concentration is equal to or less than the regulation value in the opening degree range R.

Further, the output signal of the control device 115 is a drive signal of an actuator that adjusts the opening degree of the inlet guide blade 101a.

Next, the combustion control of the gas turbine will be described.
The measured values of the turbine inlet gas temperature measured by the inlet temperature measuring device 104a and the turbine exhaust gas temperature measured by the exhaust temperature measuring device 106a are input to the control device 115. The control device 115 outputs a drive signal to the actuator of the inlet guide blade 101a so as to have an opening range R with respect to the measured value of either or both of the input turbine inlet gas temperature and the turbine exhaust gas temperature. As a result, the opening degree of the inlet guide blade 101a is changed, and the amount of air supplied is adjusted to an equivalent ratio that can maintain good combustion. Therefore, stable combustion can be maintained even when the load fluctuates and partial load operation is performed, and the NOx concentration of the exhaust gas can be kept substantially constant.
It should be noted that the case of measuring the turbine exhaust gas temperature may be a simpler measuring instrument than the case of measuring the turbine inlet gas temperature, and the measurement is simpler. Therefore, it is preferable to use the turbine exhaust gas temperature as a parameter.

Next, the structure of the premix pipe provided in the gas turbine by this combustion control method will be described.

3 to 8 show a premixer tube 1 having the structure according to the first embodiment. The upper portion of the cylindrical body portion 1a of the premixing pipe 1 is closed by a bottom plate 1b except for the central portion, and a nozzle support pipe 11 for holding the main fuel nozzle 110 is provided in the central portion of the bottom plate 1b. , Attached via the seal 11a. The side of the nozzle support pipe 11 of the premix pipe 1 is the upstream side of the main fuel flow.
Further, the lower portion of the body portion 1a, that is, the downstream side of the main fuel flow, is continuous with a cylindrical conical body portion 1c whose diameter is gradually reduced to a smaller diameter on the lower side. Further, the inclined pipe portion 1e is continuous from the conical body portion 1c so that the opening 1d is directed in a direction deviated from the direction of the axis C of the body portion 1a. Further, as shown in FIG. 4, the opening 1d has a circular shape.

An appropriate number of air holes 1a1, 1a2, 1a3, and 1a4 are formed in the body portion 1a of the premixing tube 1. As shown in the developed view of FIG. 8, the air holes 1a1, 1a2, 1a3, and 1a4 have the number of air holes 1a1 formed in the circumferential direction on the upstream side of the premixing tube 1 in the circumferential direction on the downstream side thereof. The number is larger than the number of air holes 1a2 to 1a4 formed. In this embodiment, four rows of air holes 1a1, 1a2, 1a3, and 1a4 are arranged side by side in the axis C direction, but the most upstream air holes 1a1 are 16 and the other air holes 1a1 are arranged. There are eight air holes 1a2, 1a3, and 1a4 arranged at the positions.
The positional relationship between these air holes 1a1, 1a2, 1a3, and 1a4 is shown in FIGS. 7 and 8. FIG. 7A is a cross-sectional view cut along the line 7A-7A in FIG. 4 at a plane orthogonal to the axis C, and 16 air holes 1a1 are arranged in this portion. Further, FIG. 7B is a cross-sectional view cut along the line 7B-7B in FIG. 4, which is cut at the portion of the air hole 1a2 arranged on the immediately downstream side of the air hole 1a1, and the portion is 8 The individual air holes 1a2 are arranged. The eight air holes 1a2 are arranged at positions where every other 16 air holes 1a1 overlap in the axis C direction. Further, the number of air holes 1a3 arranged on the immediate downstream side of the air holes 1a2 is eight, and as shown in FIGS. 7 (B) and 7 (C), the positions of the air holes 1a2 and It is arranged at a position offset by an angle of 22.5 ° in the circumferential direction. Eight air holes 1a4 arranged at the most downstream are arranged in the circumferential direction, and as shown in FIGS. 7 (B) and 7 (D), these air holes 1a4 are air. It is arranged at the same position as the hole 1a2 in the axis C direction.
By arranging the air holes 1a2, 1a3, and 1a4 at positions displaced by an angle of 15 °, all of the air holes 1a2, 1a3, and 1a4 are displaced in the direction along the axis C. It doesn't matter what you arrange.
Further, the diameters of the air holes 1a1, 1a2, 1a3, and 1a4 may be different from each other. In this case, it is preferable to increase the diameter of the air holes 1a1 arranged on the upstream side. Further, the diameter may be gradually reduced toward the downstream side, or the diameters of the air holes 1a2, 1a3, and 1a4 may be made equal.

Then, as shown in FIG. 2, the premixer tube 1 is arranged with the opening 1d directed toward the central portion of the combustor inner cylinder 103b. Therefore, the mixed gas is injected toward the flame ignited by the pilot fuel.
Further, as described above, each of the premixing pipes 1 is provided with a main fuel nozzle 110, and the main fuel is supplied to the main fuel nozzle 110 from the fuel supply pipe 110a via the adjusting valve 110b. To. Further, a drive signal is input from the control device 115 to the actuator that opens and closes the adjusting valve 110b.

Next, the operation of this premixing tube 1 will be described below.
In this premixing pipe 1, compressed air is introduced from the air holes 1a1, 1a2, 1a3, 1a4 formed in the body 1a with respect to the combustion gas of the main fuel injected from the nozzle 110 for the main fuel, and the combustion gas is introduced. Is diluted and mixed inside the premixing tube 1 to generate a mixed gas. The combustion gas has the highest concentration immediately after injection by the main fuel nozzle 110. In this premixing pipe 1, the number of air holes 1a1 on the upstream side is larger than the number of air holes 1a2, 1a3, 1a4 on the downstream side, so that a large amount is large from the air holes 1a1 on the upstream side. Air is introduced. Therefore, the dilution of the high-concentration combustion gas is promoted.
Further, since the air holes 1a2, 1a3, and 1a4 are arranged at different positions in the circumferential direction, the positions where the air holes 1a2 do not face, that is, the positions where the intermediate positions between the adjacent air holes 1a2 in the circumferential direction face. It is difficult for air to be introduced into the combustion gas that passes through. However, since the air holes 1a3 arranged downstream of the air holes 1a2 are arranged at positions displaced from the air holes 1a2, the combustion gas that has passed through the portion where the air holes 1a2 are not formed is allowed. It is diluted with the air introduced from the air holes 1a3. Therefore, the supplied combustion gas as a whole is evenly mixed with air, diluted to a desired state and used for combustion to generate a high-temperature, high-pressure working gas.
Since the opening 1d having a diameter smaller than that of the body portion 1a is formed in the downstream portion of the premixing pipe 1, the flow velocity of the mixed gas injected from the opening 1d becomes large. Therefore, since the fuel is injected at a high speed with respect to the flame of the pilot fuel, the flame of the ignited combustion gas does not flash back.

Then, the working gas that drives the turbine 104 is discharged from the exhaust duct 106. Since the exhaust gas discharged is low in the combustion gas concentration of the mixed gas mixed and diluted in the premixing pipe 1, the amount of NOx discharged is small.

9 to 11 show a premixer tube 2 having the structure according to the second embodiment. The same parts of the premixed pipe 2 according to this embodiment and the same parts as the premixed pipe 1 according to the first embodiment shown in FIGS. 3 to 8 are designated by the same reference numerals.
A lid 2b formed separately from the body 2a, to which the nozzle support tube 11 is attached via the seal 11a, is provided on the upper part of the body 2a of the premixing tube 2.
In the lower part of the body portion 2a, the upper end portion on the upstream side is a circular shape continuous with the body portion 2a and the diameter is gradually reduced toward the downstream side, and the lower end portion on the downstream side is formed in a square shape. Is continuous.
The upper end of the rectangular inclined pipe portion 2e continuous with the connecting body 2c is connected to the lower end of the connecting body 2c, and the opening of the lower end of the inclined pipe 2e is in the direction of the axis C. On the other hand, it is designed to point in a biased direction. That is, the opening 2d is square as shown in FIG.

Similar to the body portion 1a of the premixing tube 1 according to the first embodiment, the body portion 2a of the premixing tube 2 is provided with an appropriate number of air holes 2a1, 2a2, 2a3, 2a4. The same number of air holes 2a1, 2a2, 2a3, and 2a4 as the air holes 1a1, 1a2, 1a3, and 1a4 formed in the body portion 1a of the premixing tube 1 are arranged at the same positions. Therefore, with respect to the air holes 2a1, 2a2, 2a3, and 2a4 formed in the body portion 2a, FIGS. ) Has the same cross-sectional shape.

As in the case of the premixed pipe 1, the premixed pipe 2 is also arranged with the opening 2d directed toward the center of the combustor inner cylinder 103b as shown in FIG. 2, and ignites the pilot fuel. The mixed gas is injected toward the flame. Moreover, since the opening area of the opening 2d is smaller than the cross-sectional area of the body portion 2a, the flow velocity of the mixed gas becomes large and flashback is prevented.

A plurality of premixing pipes 1 and 2 are arranged on the circumference in the upper part of the combustor inner cylinder 103b, and the fuel supply pipe 110a for supplying the main fuel to each of the main fuel nozzles 110 provided is provided. A regulating valve 110b is interposed in the air. A drive signal is input from the control device 115 to the actuator responsible for opening and closing the regulating valve 110b.
Then, when the load of the turbine fluctuates, the adjusting valve 110b is opened and closed based on the drive signal from the control device 115, and the number of the main fuel nozzles 110 for injecting the main fuel is changed. That is, during the partial load operation, the number of main fuel nozzles 110 to be injected is reduced to reduce the injection amount of the main fuel, and the injection amount is increased as the load is increased.
For example, six premixing pipes 1 and 2 are arranged, and main fuel is injected from the main fuel nozzles 110 of the two premixing pipes 1 and 2 during partial load operation, and six mains are injected during rated load operation. The fuel is injected from the nozzle 110.
Therefore, by reducing the main fuel according to the increase or decrease of the load, the equivalent ratio can be adjusted and good combustion can be maintained.

In addition to increasing or decreasing the number of injections of the main fuel nozzle 110, it is also possible to control the combustion of the turbine by combining changes in the opening degree of the inlet guide blade 101a.
By combining the increase / decrease in the number of injections of the main fuel nozzle 110 and the change of the opening degree of the inlet guide blade 101a to control the combustion of the turbine, more stable combustion can be maintained.

In the premixing tubes 1 and 2 described above, as shown in FIG. 12, premixing air for diluting the combustion gas is supplied from the sides of the body portions 1a and 2a.
On the other hand, FIG. 13 shows a structure in which air is taken in from the upper opening 4a of the premixing tube 4. Since the premixing pipe 4 has a structure in which air is taken in from above, it is necessary to increase the distance between the canopy 112 of the gas turbine 100 and the upper opening 4a of the premixing pipe 4.
On the other hand, since air is taken in from the side in the premixing tubes 1 and 2 having the structure according to the present invention, as shown in FIG. 12, between the upper part of the premixing tubes 1 and 2 and the canopy 112. The distance can be reduced.
Therefore, the height of the gas turbine 100 can be reduced to reduce the size of the gas turbine 100.

According to the combustion control method of the gas turbine according to the present invention, stable combustion can be maintained even when the load fluctuates, and in particular, the combustion during partial load operation such as at night can be stabilized to stabilize the combustion of the gas turbine. Contributes to high-efficiency operation.

1 Premix pipe 1a Body 1b Bottom plate 1c Conical body 1d Opening 1e Inclined pipe 1a1, 1a2, 1a3, 1a4 Air holes 11 Nozzle support pipe 11a Seal 2 Premix pipe 2a Body 2b Lid 2c Connection body 2d Opening 2e Inclined pipe 2a1, 2a2, 2a3, 2a4 Air hole 100 Gas turbine 101 Air suction port 101a Inlet guide blade 102 Compressor 103 Combustor 103a Combustor outer cylinder 103b Combustor inner cylinder 104 Turbine 104a Inlet temperature measuring instrument 105 Main shaft 106 Exhaust duct 106a Exhaust temperature measuring instrument 110 Main fuel nozzle 110a Fuel supply pipe 110b Adjusting valve 111 Pilot fuel nozzle 112 Canopy 115 Control device C axis R Opening range

Claims (5)

It is equipped with a compressor, a combustor by premixed combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied.
An inlet guide wing is placed on the intake side of the compressor,
Measure one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature,
Based on the relationship between the fuel equivalent ratio measured and set in advance and one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature.
A gas turbine combustion control method comprising adjusting the opening area of an inlet guide blade with respect to a measured temperature of a turbine inlet gas temperature or a turbine exhaust gas temperature. It is equipped with a compressor, a combustor by premixed combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied.
An inlet guide wing is placed on the intake side of the compressor,
A nozzle for pilot fuel is arranged in the center of the combustor inner cylinder,
Around this pilot fuel nozzle, multiple premix pipes equipped with a main fuel nozzle are arranged.
Measure one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature,
Based on the relationship between the fuel equivalent ratio measured and set in advance and one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature.
A gas turbine combustion control method comprising adjusting the opening area of an inlet guide blade with respect to a measured temperature of a turbine inlet gas temperature or a turbine exhaust gas temperature. It is equipped with a compressor, a combustor by premixed combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied.
An inlet guide wing is placed on the intake side of the compressor,
A nozzle for pilot fuel is arranged in the center of the combustor inner cylinder,
Around this pilot fuel nozzle, multiple premix pipes equipped with a main fuel nozzle are arranged.
Measure one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature,
Based on the relationship between the fuel equivalent ratio measured and set in advance and one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature.
A method for controlling combustion of a gas turbine, which comprises adjusting the number of premixing pipes for injecting main fuel with respect to a measured temperature of a turbine inlet gas temperature or a turbine exhaust gas temperature. It is equipped with a compressor, a combustor by premixed combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied.
An inlet guide wing is placed on the intake side of the compressor,
A nozzle for pilot fuel is arranged in the center of the combustor inner cylinder,
Around this pilot fuel nozzle, multiple premix pipes equipped with a main fuel nozzle are arranged.
Measure one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature,
Based on the relationship between the fuel equivalent ratio measured and set in advance and one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature.
For the measured temperature of the turbine inlet gas temperature or the turbine exhaust gas temperature
Adjusting the opening area of the inlet guide wing,
Or / and adjusting the number of premix pipes that inject the main fuel,
Combustion control method for gas turbines. The method for controlling combustion of a gas turbine according to any one of claims 1 to 4.
The equivalent ratio is obtained from the relationship between the metal temperature of the turbine blade and the turbine inlet gas temperature or the turbine exhaust gas temperature in a state where the values satisfy the respective reference values of combustion vibration, combustion efficiency, and exhaust gas NOx concentration. A method for controlling combustion of a gas turbine, which comprises adjusting the opening area of an inlet guide blade from a measured temperature based on this relationship.

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